Roof Truss Heel Height Calculator

Unit System

Clear Span (wall to wall)

Use ft for Imperial, m for Metric.

Eave Overhang

Horizontal length beyond wall line.

Heel Type Focus

Project Name / ID

Designer / Engineer

Location / Region

Code Reference

Ground Snow Load

psf or kPa, documentation only.

Roof Live Load

Roof Dead Load

Min Code Heel Height

Enter in inches.

Pitch Mode

Rise (for X in 12)

Example: 6 gives 6 in 12 pitch.

Pitch (degrees)

Used when Pitch Mode is Degrees.

Top Chord Depth

In inches.

Bottom Chord Depth

In inches.

Insulation Input Mode

Choose direct depth or R-based.

Insulation Thickness

Used when Direct Thickness is active.

Target R-Value

Used when Target R-Value is active.

Insulation Type

Custom R per inch

Custom R per mm

Ventilation Clearance

Sheathing Thickness

Roof Covering Thickness

Ceiling Finish Thickness

Bearing Width

Why Accurate Heel Height Matters

Heel height controls continuous insulation, ventilation pathways, and truss bearing at exterior walls. Undersized heels increase thermal bridging, ice damming risk, moisture problems, and non-compliance. This calculator highlights when raised heels are justified for performance.

Standard vs Energy Heel Comparison

Heel Type	Typical Use	Insulation at Eave	Impact
Standard Heel	Mild climates or lower insulation requirements	Often compressed above exterior wall plate	Lower cost; greater thermal bridging; possible code limitations
Energy Heel	Higher R-value, cold or mixed climates	Full-depth insulation maintained at eave	Taller heel; improved efficiency and easier compliance

Key Inputs That Influence Heel Height

Roof pitch and span define bearing-to-ridge geometry.
Top and bottom chord depths set baseline heel thickness.
Required R-value and insulation type control insulation depth.
Vent clearance and roof layers add vertical build-up.
Minimum code heel values override smaller geometric heels.
Bearing width affects plate seat and heel configuration.

Example Heel Height Data Table

Sample scenarios illustrating how pitch, insulation strategy, and layers affect heel height.

Clear Span	Pitch	Insulation Input	Vent	Sheathing + Cover	Standard Heel	Energy Heel	Extra Height
40 ft	6:12	R-49 fiberglass	1 in	0.75 in	5.0 in	13.5 in	8.5 in
30 ft	4:12	R-38 cellulose	1 in	0.75 in	4.0 in	11.5 in	7.5 in
12 m	30°	300 mm insulation	25 mm	23 mm	170 mm	348 mm	178 mm

Formula Used for Heel Height Calculation

Slope (rise-in-12) = rise / 12; angle θ = arctan(slope).
Standard Heel ≈ Bottom Chord Depth + Top Chord Depth × sin(θ).
Insulation thickness from R: Thickness = Target R / (R per unit).
Required Energy Heel Depth = Insulation + Vent + Sheathing + Roof Cover.
Energy Heel = max(Standard Heel, Required Depth, Minimum Code Heel).
Extra Height = Energy Heel − Standard Heel.

Use for layout guidance only. Final truss design must be engineered and code-compliant.

How to Use This Calculator

Select unit system and enter clear span, overhang, and bearing width.
Provide project details, loads, and applicable code references.
Set roof pitch using rise-in-12 or degrees.
Enter chord depths and insulation requirements or R-value targets.
Add vent clearance, sheathing, and roof covering build-up.
Specify minimum code heel if required.
Choose heel type focus and run the calculation.
Review heights, geometry, and export CSV or PDF for coordination.

Treat results as a coordination aid alongside sealed truss engineering documents.

Frequently Asked Questions

1. Can this tool replace engineered truss design?

No. It provides conceptual heel heights for coordination. Final truss geometry, reactions, plate design, and connections must be completed, checked, and approved by a qualified engineer or truss manufacturer.

2. Does it account for snow, wind, or seismic loads directly?

No. Load fields are for record only. Heel height results are geometric and insulation-based. Full structural analysis for snow, wind, and seismic actions must be performed separately using appropriate design tools.

3. Can I use metric inputs with imperial insulation data?

Yes. Select your preferred unit system, then enter custom R-values so outputs align with the specific insulation product data sheets and requirements.

4. What is an energy heel in this calculator?

An energy heel is a raised heel providing full insulation depth, ventilation clearance, and roof layers above the wall plate without compression at the eave.

5. Can I export results for submittals and coordination?

Yes. After calculating, use CSV for tabular data or PDF for a concise summary to share with project teams, reviewers, and truss suppliers.

6. How should I choose minimum code heel height?

Base it on governing codes, energy standards, specifications, or engineer guidance. When uncertain, confirm with the authority having jurisdiction or the truss engineer before finalizing drawings.